The Benchmark Assessment asked this:

Which of the following statements explains why recycled plastics must be separated by their recycling code?

• A: The six different recycling codes represent polymers made of long chains of repeating clusters of atoms, called monomers.
• B: The six different recycling codes represent different isotopes with varying degrees of nuclear stability.
• C: The six different recycling codes represent different elements on the periodic table.
• D: The six different recycling codes represent different macromolecules with no elements in common with each other.

The Following Answers Were Awarded Full Credit. Can you tell why?